Puzzle · Logic Puzzle
Akari Light Up
Play Akari Light Up online. Place bulbs to illuminate every white square. Bulbs cannot shine on each other, and wall numbers count adjacent bulbs.
The game's own interface may still be in English.
Overview
Akari, also known as Light Up, is about placing lamps so their beams cover every open square. A bulb illuminates its own cell and continues horizontally and vertically until a black wall stops the light. Two bulbs may not shine directly on each other. Numbered walls add local constraints: the number counts bulbs immediately above, below, left and right of that wall, not distant bulbs in the same line. Unnumbered walls simply block light. The whole board must be illuminated while satisfying both kinds of rule. The locally compiled Light Up engine provides new generated boards and different settings. There is no action timer, so you can pause to reason about a dark corridor before committing another bulb.
How to Play
Click a white square to place a bulb, then click it again to remove it. Use a secondary click to mark a square where a bulb should not go. On a phone, the Secondary toggle provides that marking action without requiring a long press. Observe how each bulb lights its row and column up to the nearest walls. A completed board has no dark white squares, no bulbs facing each other, and the correct adjacent bulb count for every numbered wall. Undo reverses your latest choice.
Tips & Strategy
Mark the neighbours of a zero wall as unavailable immediately. A four forces bulbs on all four sides, while a three beside the outer edge may also have every possible position fixed. Once a bulb lights an unobstructed corridor, additional bulbs anywhere along that corridor are forbidden. Look for an unlit square with only one remaining place that could illuminate it; that deduction can be stronger than the nearest numbered clue. Remember that a lit cell may still be forbidden as a bulb location, and that meeting all wall numbers is insufficient if a remote corner remains dark.
About this version
Akari Light Up uses the locally compiled lightup engine from Simon Tatham’s Portable Puzzle Collection. The original authors retain credit under the MIT license. SonoTap provides the browser adaptation and this guide.
Controls
- Mouse
- Click a white square to place a bulb, then click it again to remove it. Use a secondary click to mark a square where a bulb should not go. On a phone, the Secondary toggle provides that marking action without requiring a long press. Observe how each bulb lights its row and column up to the nearest walls. A completed board has no dark white squares, no bulbs facing each other, and the correct adjacent bulb count for every numbered wall. Undo reverses your latest choice.
- Touch
- Tap or drag on the board using the same rules as mouse input. Enable Secondary for the alternate mark; numeric games also provide on-screen keys.
Features
- Place bulbs to illuminate every white square. Bulbs cannot shine on each other, and wall numbers count adjacent bulbs.
- Local open-source game engine with original author credits
- Generated puzzles and the upstream Type settings
- Undo and restart controls
- Touch input and a secondary-action toggle
Frequently asked questions
What is the goal in Akari Light Up?
Place bulbs to illuminate every white square. Bulbs cannot shine on each other, and wall numbers count adjacent bulbs.
What is a useful first deduction in Akari Light Up?
Mark the neighbours of a zero wall as unavailable immediately. A four forces bulbs on all four sides, while a three beside the outer edge may also have every possible position fixed.